So, I beat the AI on "Challenging" and moved on to "Tough". A few interesting things I noticed:
1. AI tends to build small/tiny ship sizes rather than corvette or above. I am not sure if it makes sense maintenance-wise, but AI sure kicked my but in this area. I was building three ship groups with large hulls and it took me a wile to build. When in combat one or two groups of 4-5 smaller ships destroyed all of mine. I am pretty sure that it takes a lot less resources and time to build a large fleet of small craft than small fleet of individually larger ships. Did anyone else notice this?
2. Another thing I noticed on "Tough" is that AI no longer builds weapons in just one category. I constantly encountered fleets with mixed weapons/defences and could not figure our one counter to use. I mean all AI races build mixed weapons so I ended up creating mixes as well, unfortunately for me, large fleets of small craft pretty much knocked me out.
Any thoughts on how to counter mixed weapons/defenses strategy by AI?